Monday, February 11, 2008

rTSS part 2

My friend, Lee Robb (who tends to see things more clearly than I do at times), had the following comment regarding my unhappiness with running TSS in WKO+ (see previous blog post for my take on it):

"Maybe I'm misunderstanding. Daniels defines T-pace as a 50-60 minute effort, that which elicites a steady state of lactate accululation. 10k intervals for a 30' runner is a vo2max workout (I-pace), wherease 10k intervals for a 60' runner is a threshold workout (T-pace). Threshold pace for a 30' runner is closer to their 20k race pace. "

Initially, I was irritated...not because of what Lee said, but because immediately after reading it, I knew I was wrong in my "logic" somewhere. His point made sense, and worse yet, was right. So I re-evaluated my position and tried to figure out where I went wrong and why despite the above being true, I still didn't like how rTSS was calculated in WKO+.

Physiologically, I have no problem with the threshold pace being set as an hour. LT is usually defined as lactate accumulation over a period of about an hour, regardless of sport. Many swimmers judge their training paces based on their 3K swim time (about an hour), which sould be their approximate LT pace. Okay, so I'm at peace with the idea that WKO+ uses a 1-hour pace as threshold. But there is still something that doesn't sit right with me, and that's what I had to put a lot of thought into.

I finally figured it out. I don't like it from an aesthetic standpoint. I'm planning my season based around TSS for each sport, not time or distance (here). What I would like is to have TSS broadly comparable among the 3 sports so that a TSS of 80 on the bike feels like a run TSS of 80 feels like a swim TSS of 80. But with threshold run pace as a function of a 1-hour time, they aren't that comparable. In my opinion, WKO+ still underestimates the "true" TSS for running. For example, a TSS of 150 on the bike feels nothing like TSS of 150 on the run. The latter would have me taking several days rest, whereas the former would require 1 day rest max. So, I finally figured out why I don't like it...turns out I have to eat crow about it not accurately reflecting a good LT pace, but I still think I'm right on how it underestimates rTSS.

1 comment:

scott said...

Wanting a numeric stress score which evenly equates all 3 sports is a complex matter. A universal number would assume that we all recover from swimming, biking, and running at the same rate.
In theory, what you seek is possible, but I believe it would be very athlete/sport dependent. WKO+ allows one to define the moving averages (MA) of ATL and CTL for this very reason. The amount of time an athlete can hold fitness and shed fatigue are unique to that athlete. Additionally, each sport will affect the athlete's body differently than another.
The MA's in WKO+ Performance Management Chart (PMC) are just empirical default values you may need to modify for both the individual athlete and their respective sport(s).
Try cusomizing ATL and CTL MA's within the PMC for each athlete and each athlete's sport.
I believe further clues can be found by testing the athletes Rate of Fatigue and by running a statistical analysis of the Impulse Response Model (thanks Dr. Phil Skiba).
This is an interesting and complex puzzle. It would be nice to know how a 150 TSS bike ride is going to affect my next run. And how a 150 rTSS is going to affect my next ride.
I think it is possible to learn these values, but everyone will have to customize their own formula a bit.